1. Field of the Invention
The present invention relates to catheters for delivering fluids intravenously to a patient. In particular, the present invention provides an improved catheter which can be expanded once inserted so to provide ease in insertion while permitting greater fluid flow during operation.
2. Description of the Prior Art
One major problem facing emergency medical personnel is that in times of trauma the circulatory system of a patient will contract to reduce blood flow. As a result, it is often very difficult to insert a catheter intravenously to provide necessary medication to the patient. Medical personnel are often forced to use a catheter of much smaller gauge than is necessary in order to be able to insert it into a contracted vein. This limits the amount of medication which can be delivered to the patient and complicates an already serious situation. Alternatively, medical personnel may have to make repeated attempts to insert a larger catheter tube, with resulting delay in providing medication and possible damage to the patient's skin and veins.
Although it has been suggested to employ expandable drainage tubes for other medical procedures, such a concept has not been applied to increase the fluid carrying capacity of an intravenous catheter once inserted. In U.S. Pat. No. 4,716,901 issued to Jackson et al. an expandable trocar is disclosed to introduce exploratory instruments or to drain a body cavity. This device is large, unwieldy and completely unsuitable for use in the delicate environment of intravenous catheterization. U.S. Pat. No. 4,228,802 issued to Trott discloses an expansion means to hold a drainage catheter in place in a bladder. Not only is the expansion means of this device unrelated to providing increased fluid carrying capacity, but, again, this device is unsuitable for use in an intravenous system. In U.S. Pat. No. 4,245,635 issued to Kontos an intravenous catheter is disclosed including valving to reduce or cease the flow through the catheter. This patent provides no teaching or suggestion that it may be beneficial to increase the size and fluid carrying capacity of the catheter once it is installed.
It is accordingly a primary object of the present invention to provide an intravenous catheter which may be readily inserted at a minimum contracted diameter and which may be expanded in size to increase its fluid carrying capacity once installed.
It is a further object of the present invention to provide such an intravenous catheter which includes means to maintain the catheter at its expanded size once installed.
It is an additional object of the present invention to provide such an intravenous catheter which integrates with existing medical apparatus and techniques and requires minimum training and time to install and use.
It is another object of the present invention to provide such an intravenous catheter which is of relatively simple construction and which can be manufactured at minimal additional expense.
Additional objects of the present invention will become apparent upon consideration of the following description of the present invention.